1. Technical Field
The present invention relates generally to the metallurgy and the foundry industries and more specifically, to a device for transfer of molten metal.
2. Description of the Prior Art
Known in the present state of the art is a device for transfer of molten metal (No. SU, A, 679,783) having an MHD pump comprised of a ceramic cylindrical housing provided with double walls and having a solenoid installed between the walls. The inner space of the housing is divided by a cross partition into an upper space and a lower space, and the partition has an opening provided therethrough in its central portion. In the upper space of the housing there is provided a graphite electrode installed with a clearance relative to the cross partition so that the space bounded by the cross partition and the graphite electrode forms a working chamber of the MHD pump. A pipe for discharge of molten metal is provided in the housing wall, whereas the working chamber communicates with the molten metal bath through the agency of the lower space and the opening in the cross partition.
A magnetic field in the working chamber of the MHD pump is produced by a solenoid connected to a power supply source. Transfer of molten metal contained in the working chamber is effected due to interaction between the electric current passing through molten metal and the magnetic field produced by the solenoid.
However, due to the fact that the magnitude circuit in such a device is made open and the magnetic induction field lines are closed through an air gap, the amount of magnetic induction within the working chamber will be low. In the above-described device, the working chamber is not hermetically sealed, which restricts the metal pressure developed by the MHD pump.
Known presently is another device for transfer of molten metal wherein metal is heated as it is being transferred by the MHD pump (No. SU, A, 649,179). Such a device comprises a metal housing which incorporates a working chamber hermetically connected with a pipe for the discharge of molten metal. The housing is made from a material having high magnetic permeability and makes part of the magnetic circuit, its outside surface being enclosed by a solenoid.
In the above-mentioned device, transfer of molten metal filling the working chamber occurs due to interaction between the electric current passing through molten metal contained in the working chamber and the magnetic field produced by the solenoid, the magnetic induction vector being directed parallel to the longitudinal axis of the chamber.
However, the above-described components of the magnetic circuit of the MHD pump fail to provide a maximum obtainable amount of magnetic induction in the working chamber, due to the fact that magnetic induction lines of force are completed through air, whereas the housing wall made of steel partly shunts the magnetic field in the working chamber. Besides, part of the current passing through the working chamber flows through the end walls of the chamber rather than through the molten metal, thus also reducing the efficiency of the MHD pump.